ENDC & NEDC

Mind Map: LTE - NR Interworking Types

Central Idea

Types of LTE - NR Interworking: ENDC and NEDC

Main Branches

1. ENDC (Eutra / NR Dual Carrier)

  • Definition

    • LTE as MCG (Main Cell Group)

    • NR as SCG (Secondary Cell Group)

  • Deployment

    • Dominant form of deployment

    • Core Network based on LTE Core

  • Traffic Management

    • Downlink Traffic

      • Always split between LTE and NR

    • Uplink Traffic Options

      • Option 1: All uplink through LTE only

      • Option 2: Uplink split between LTE and NR

        • Ratio configured by RRC

  • UE Interaction

    • Detect SSB of NR cell

    • Perform RACH procedure to NR

2. NEDC (NR/Eutra Dual Carrier)

  • Definition

    • NR as MCG (Main Cell Group)

    • LTE as SCG (Secondary Cell Group)

  • Deployment

    • Primarily done in specification

    • Rare real-world examples

  • Traffic Management

    • Similar structure to ENDC but with NR as primary

  • UE Interaction

    • Similar to ENDC but focused on NR detection

Summary

  • ENDC is the prevalent method for LTE-NR interworking, leveraging LTE as the main cell and NR as an enhancement.

  • NEDC exists mainly in specifications with limited practical deployment, focusing on NR as the primary cell.